A technology which assists a driver to conveniently and safely drive a car in complex and various road environments has been developed. Therefore, many vehicles adapt a driving assistance system (DAS). In order to adapt the DAS, a sensor function is also actively being developed.
When the vehicle drives in the tunnel, a sudden change of illumination among road environments may hinder a vehicle sensor from precisely recognizing an object. Therefore, in recent years, a technology which detects streetlamps of a tunnel in a predetermined pattern to determine whether the vehicle enters a tunnel or escapes the tunnel is being studied.